COVID-19 Detection Using a 3D-Printed Micropipette Tip and a Smartphone

Area of Science:

• Biotechnology
• Nanotechnology
• Infectious Disease Diagnostics

Background:

• The COVID-19 pandemic highlighted critical gaps in virus testing accessibility and speed, particularly in resource-limited areas.
• Existing diagnostic methods often require specialized equipment and trained personnel, hindering widespread deployment during public health emergencies.

Purpose of the Study:

• To develop a low-cost, rapid, and accessible COVID-19 diagnostic assay utilizing a synthetic SARS-CoV-2 sensor and smartphone technology.
• To optimize the assay for saliva samples and evaluate its performance against established methods like qPCR.

Main Methods:

• A synthetic polymeric sensor (COVRs) for SARS-CoV-2 spike protein was developed on silica nanoparticles.
• The assay employed 3D-printed micropipette tips with anti-SARS-CoV-2 antibodies and a colorimetric detection system using streptavidin-poly-horseradish peroxidase.
• Smartphone imaging and analysis via the Color Grab app and ImageJ were used for quantification.

Main Results:

• The assay achieved a limit of detection of 200 TCID50/mL in artificial saliva.
• COVRs demonstrated high binding affinity for SARS-CoV-2 spike proteins over salivary proteins.
• Results from human saliva samples showed excellent correlation with quantitative PCR (qPCR) viral load measurements (p = 0.0003, r = 0.99).

Conclusions:

• The developed low-cost, mix-and-read COVID-19 assay is a viable and accurate diagnostic tool.
• Smartphone-based detection offers a scalable and accessible solution for SARS-CoV-2 testing, addressing limitations in resource-limited settings.